Does Nick have a crush on the great ghasby?

Probably but it would not have been revealed in a standard type novel like that. Novels revealing male on male crushes were highly specialised at that time and it would have kept the book out of the mainstream. Men were extremely good at sublimating and concealing homosexual erotic feelings in that era.

I agree with the answers "envy" of Jay's wealth and good looks, and "fascination" with his charisma and his unknowableness. He is a guy Nick can't categorize and forget. I don't think Nick shows signs of love or possessiveness for Jay, but some people have said Nick was predisposed to erotic feelings for men. If you think so, then you will find evidence.

it would have been considered ENVY at the at the time.

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